Electric screen



ATTORNEY? May 11, 1937. WARD ELECTRIC SCREEN Filed Aug. 26, 1936 2Shets-Sheet 1 15/ INVENTOR flwca cz WGIT'CZ BY W W WITNESSES H. WARDELECTRIC SCREEN Filed Aug 26, 1936 2 Sheets-Sheet 2 INVENTOR JfcwarriWard BY WV ATTORNEY WITNESSES.

Patented May 11, 1937 UNITED STATES PATENT OFFICE R. Kenan, Jr.,

Lockport, N. Y.

Application August 26, 1936, Serial No. 97,951

5 Claims.

This invention relates to improvements in electric screens and has foran obj ect the provision of an improved screen for destroying flies andsimilar insects.

Electric insect screens of several types have been available prior to myinvention. However,

difficulties of various kinds ha tered with these screens.

ve been encoun- Thus the insulating mechanism was unsatisfactory andshort circuits frequently developed especially when the screens becamewet as during a rainstorm, and also if one of the wires broke the entirescreen became inoperative.

Furthermore, many of the screens were ineflicient because they formed avisible barrier to the insects or because they failed to attract andeven repelled the reason or another.

insects for one It is accordingly a prime object of the presentinvention to overcome the difficulties heretofore encountered and toprovide a satisfactory electric insect screen of improved 0 to provideeffective insulation circuiting even under adverse onstruction so aspreventing short conditions, and

which will operate in an efficient manner to electrocute a maximumnumber of insects.

For a fuller understanding of the invention reference should be had tothe accompanying drawings which illustrate a preferred form of myinvention.

Fig. l is an elevation of the screen embodying my invention with thecentral portions omitted; Fig. 2 is a sectional View in the direction ofthe arrows on the line 2-2 of Fig.

Fig. 3 is a sectional view in the direction of the arrows on the line3-3 of Fig.

Fig. 6 is a view of a modified ing plate.

In the accompanying type of supportdrawings the numeral I0 indicates aframe made of suitable material, preferably wood, and shaped so as tofit snugly in the opening which is to be screened.

In the accompanying drawings the screen illustrated is suitable for usein a window and accordingly is rectangular in shape and is formed of twoupright members ll suitably connected at .heir upper and lower ends tohorizontally disposed cross members I2. Across the open in the mannerhereinafter frame I support, described, a plurality of wires 0 portionof the f relatively small gage, adjacent wires being of oppositepolarity and being spaced apart a suflicient distance to avoid shortcircuiting but being close enough to electrocute a fly or similar insectattempting to pass between the wires. I have found that the mostsatisfactory results are secured by disposing the wires in horizontalposition.

The mechanism which I employ for thus supporting the wires includes apair of channel mem bers indicated by the numeral I4, formed of a metalof high electrical conductivity such as bronze, brass, or the like. Thechannel members are disposed adjacent the sides II of the frame and areparallel thereto, each being secured to its respective side member by apair of spaced porcelain insulators indicated at l5 and positionedadjacent the ends of the channel members.

The insulator should be of very high quality so as to preventshort-circuiting and for this purpose I preferably provide insulators ofthe type illustrated formed of a body portion I6 frustoconical in shape,provided with a peripheral flange ll at the base thereof and having acentral axial bore l8 extending therethrough, the bore being formed intwo sections, a larger section extending from the base of the insulatorpast the center thereof, and a small section extending from the largersection to the end. of the insulator, thereby providing a shoulder iii.

In assembling the device a bolt 2| of suitable size is projected throughthe enlarged portion of the bore and extended outwardly through the endof the insulator until the head 22 of the bolt engages the shoulder IS.The end of the bolt is then projected through an opening formed in theside of the channel member and is held in position by means of a nut 23screwed on the end of the bolt. The flange I! is then preferablycountersunkin the inner edge of the frame as indicated most clearly inFig. 3, andheld in position by means of the screws passing throughopenings formed in the flange and imbedded in the wood of the frame.

The confronting faces of the channel members 14 are provided with slots25 as indicated most clearly in Fig. l, the slots in each channel memherbeing positioned in substantially the same horizontal plane and servingto support one group of wires in position across the face of the screen.The wires should be formed of a metal of high 5 electrical conductivitysuch as brass or bronze, and I preferably employ spring tension wiresalthough other type of wires may be used. Thus I have illustrated coilwires which have been extendedoutwardly against the tension of the 55coils and which are held in position in the slots on the confrontingfaces of the channel members 14 by means of small loops 21 formed on thetwo ends of each wire. Instead of spring coil wires straight wires, heldtaut between the slots in the two channel members, may be employed.

The wires 25 of the first group of wires which are thus supported by thechannel members I 4 are all connected to one pole of a suitable sourceof current supply as by means of the lead wire 28 connected at one endto the source of current supply (not shown) and at the opposite end tothe spring clip 29 having suitable electrical connection with one of thechannel members M.

A second group of wires preferably formed in the same manner as thefirst group and indicated by the numeral 3! are arranged parallel to thefirst group of wires in alternate relation thereto and are spacedtherefrom a suflicient distance to prevent short-circuiting but so as toprovide for the electrocution of any fly or similar insect that mayattempt to pass between the Wires. The means for supporting the secondgroup of wires comprises a pair of plates 32 secured adjacent the outersurface of the frame by suitable means such as the screws 33 at the twosides thereof and extending inwardly from the edge of the frame asufiicient distance to overlie the vertical plane of the insulators l5and the channel members 14 thereby affording protection to those membersfrom adverse external conditions such as driving rainstorms. The metalplates are preferably formed of a metal of high conductivity such asbronze, brass, Monel metal, orthe like.

For securing the wires 3! substantially in the same vertical plane asthe group of wires 26 and in alternate relation thereto, I provide aplurality of posts 3 3 secured to the inner surface of the plates 32 bysuitable means such as brazing soas to provide strength and insure goodelectric conductivity, and so spaced that one post projects between eachadjacent pair of wires 26 of the first group of Wires near the endsthereof as shown most clearly in Fig. 1. Each of the posts 34- isprovided with a slot 35- adjacent the upper end thereof so that thewires 3! will be held in position in the slots by means of the loops 2'!in the same manner that the wires 26 are held in place.

Instead of the posts 34 I may employ the tongues: 36. formed integralwith the plates 32 and turned inwardly at right angles thereto. Each ofthe tongues is provided with a slot 36 adjacent its upper end forreceiving the end of the wires 3 land for holdingthe wires in positionas prev-iously described. The second group of wires 3| is connected tothe other pole of the source of current supply to which the wires 26 areconnected, and for this purpose I provide a spring clip 38 connected bymeans of bolt 39 to one of the plates 32 and having connection with thelead wire 49- which leads to the opposite pole of the: same source ofcurrent supply to which the lead. wire 28 is connected.

I have found that highly satisfactory resultsare obtained by employingelectric currents of relatively high voltage such as from between 3500to 5000 volts at 8 to 12 milliamperes, and for this purpose the ordinaryhouse current of 110 volts maybe converted by means of a transformer- Itwill be understood by those skilled in: the art, however, that othervoltages may be employed. It should. be understood that wires oftheproper gage and capacity should be employed. I have found that the mostsatisfactory results are obtained by using wires not larger than 20 gagemade of material having a high electric conductivity such as brass orbronze. I have also found that very satisfactory results are obtained byusing wires under spring tension as illustrated and described. It is tobe understood, however, that wires of different gage and not underspring tension may also be employed.

The screens embodying my invention may be used in many differentassociations as, for instance, for protecting the entranceways andwindows of buildings, such as dwelling houses, barns and the like. Aninsect seeking to enter through the screen will contact two adjacentwires 26 and 3| completing the circuit therebetween and will thus beelectrocuted.

Because of the improved construction herein illustrated and described,my screen will operate for long periods of time without the usualdifficulties heretofore encountered with electric insect screens. Theinsulation will operate satisfactorily preventing short circuits evenunder the most adverse conditions such as rainstorms and the like.

It should be understood of course that medi fications may be made in theillustrated and described embodiment of my invention Without de partingfrom the invention as defined in the accompanying claims.

I claim:

1. An electric insect screen comprising a frame, a pair of channelmembers having slots formed at one side thereof secured to oppositesidesof the frame with the slots inconfronting relation, each of thechannel members being secured to the frame by a pair of spacedinsulators, a group of Wires connected between the two channel membersand supported in the slots thereof. a second group of wires parallel toand spaced from the first group and supported in alternate relationthereto, and means for connecting the first group of wires to one of thepoles and the second group of wires to the other pole of a source ofelectric current.

2. An electric insect screencomprising a-frame, a pair of channelmembers having slots formed at one side thereof secured to oppositesides of the frame with the slots in confronting relation, each of thechannel members being secured to the frame by a pair of spacedinsulators, a group of wires connected between the two channel membersand supported in the slots thereof, a pair of spaced plates securedadjacent the outsideo-f the frame at the two sides thereof in a planeoverlying the channel members and insulators so as to afford protectionthereto, a second group'of wires spaced from the first group and havingmeans for supporting them on said plates in alternate rela tion to thefirst group of wires, and means;for connecting the first group of wiresto one of the poles and the second group of wires to theother pole of asource of electric current.

3; An electric insect screen comprising aframe, a pair of channelmembers having slots formed in one side thereof secured to oppositesides of the frame withthe slots in confronting relation, each of thechannel members beingsecured to the frame by a pair of spacedinsulators, each of said insulators comprising a porcelain body securedat one end to the frame and havinga central axial bore therethrough,thebore being larger at the frame end than at the other end so astoprovide aninternal shoulder intermediate the two ends of the bore andbeing secured to the channel member by means of a nut and bolt extendingthrough a portion of the channel member and the bore from the shoulderformed therein, a group of wires connected between the two channelmembers and supported in the slots thereof, a pair of spaced platessecured adjacent the outside of the frame at the two sides thereof in aplane overlying the channel members and insulators so as to affordprotection thereto, a second group of wires spaced from the first groupand having means for supporting them on said plates in alternaterelation to the first group of wires, and means for connecting the firstgroup of wires to one of the poles and the second group of wires to theother pole of a source of electric current.

4. An electric insect screen comprising a frame, a pair of channelmembers composed of conducting material having slots formed in one sidethereof secured to opposite sides of the frame with the slots inconfronting relation, each of the channel members being secured to theframe by spaced insulators, a first group of wires having electricalconnection between the two channel 25 members and supported in the slotsthereof, a

pair of spaced plates formed of conducting material secured adjacent theoutside of the frame at the two sides thereof so as to overlie thechannel members and insulators affording protection thereto, a secondgroup of wires spaced from the first group and having electricalconnection with and being supported by said plates in alternate relationto the first group of wires, and means for connecting one of the channelmembers to one pole and for connecting one of the plates to the otherpole of a source of electric current.

5. An electric insect screen comprising a frame, supporting bars securedto the frame by means of spaced insulators, a first group of wiresconnected between the bars, a pair of spaced plates secured adjacent theoutside of the frame and in a position to overlie the bars andinsulators and afford protection thereto, a second group of wires spacedfrom the first group and supported by the plates in alternate relationto the first group, and means for connecting one group of wires to onepole and the second group to the other pole of a source of electriccurrent.

HOWARD WARD.

